We had made our own a few years ago after purchasing a new engine. Didn't want to drill into the engine to mount the pulley. We bought webbing, connectors and "D" rings and sewed them up. They kept coming undone and finally one got shortened up in the prop. I just tied a line around it temporarily.
My new Idea was to go to PetsMart and get two properly sized all nylon web dog collars. They were $5 each and worked perfectly. I put the small block on the doggy chain "D"ring and then tightened them to fit the lower unit just above the prop.
I like the fact that the line pulls from the rear of the engine and not off to the side much. My previous engines had been drilled and I did not want to copy that. Would have to make and eye or mount for the pulley and a longer bolt maybe.